I have google one SIT as an example, it uses RS-232 standard for communication.It could very well be used with the above mention PICs.
This one --> www.telemonitor.com/data/tmi2-sa.pdf
Well Im looking for a microcontroller(pic) for the STIM which I will interface a temperature sensor, and good for TEDS storage( transducer electronic data sheet) and can be transmitted the data via IRDA to the PC.